the rook

Just got the car back from the shop so won't be getting on it for about 500 miles but I wanted to give an initial review.

First let me say that this is a race inspired setup so if you're looking for a stock feel then don't buy this. LOTS of chatter. My mechanic actually called JWT to verify that it is supposed to chatter that much and it is. I'm told it will diminish over the course of 1000 - 1500 miles. Honestly doesn't bother me because I've had lightweight flywheels on other cars and I was prepared. Poly bushing could factor in.
As for the poly bushing, I'm somewhere between a muscle car and a Harley!!! Incredible rumble noticeable on start up and through the entire rpm range. It's a completely different car.
The performance is much improved even during moderate acceleration. The transmission has a "hook up" to it. The clutch pedal isn't too stiff at all for me, even with the ss clutch line. It's an extremely crisp shifting unit as well. The pick up is very much improved. The flywheel is half the stock weight so that was to be expected. But I say again, this is a pure performance setup. You will have a car that feels NOTHING like stock. No dual mass dampened flywheel. You feel everything. Lol. But I love it!!!!
I'll report back as I learn and experience more .

the rook

So I decided that there was just way too much vibration in my car and that if they polyurethane transmission mount was going to cause that kind of noise and vibration that I was just going to do without it. Upon removing the old transmission mount I discovered that all of the bolts were torque down so tight that I had to use a breaker bar to get them off. These bolts three in particular that hold the bushing in place are a 40 pounds per square inch torque spec. Since I had it apart I went ahead and put the rubber bushing in for now just to see what was going to happen. Amazingly I have almost no chatter noticeable in the cab and absolutely no engine or transmission torque vibration whatsoever. So the clutch and flywheel setup is actually very nice. Nice deep clutch. Not too stiff. The RPM's crank fast with a lightweight flywheel and I definitely notice a difference in performance for the good. So upon further review every issue that I had with this setup was entirely due to poor mechanical work. Now that I have the bushing torque properly my car drives incredible. I will report back after I put another 300 miles on the clutch and have an opportunity to get on it.

On a side note now I am very curious as to whether or not I should go ahead and try the poly bushing again and just make sure that it is mounted correctly. lol

the rook

Just got to the 500 miles break in marker on the way to work tonight. So far so good. Clutch engages smooth yet crisp. Especially at higher rpm. I haven't gone all out yet to test it but I'm sure within the next few days I'll lay some rubber on a launch and fly through the gears.... ya know..... just to see how well I pick up with that flywheel. It's been difficult to restrain myself for the last couple weeks. Lol.
But all in all the clutch seems like an excellent purchase. It's given me more of a performance feel inside the cab for sure. Chatter is noticeable but hardly annoying. However if I were into the smooth and quiet luxury feel (I guess I wouldn't have bought a sports car!!)
this clutch wouldn't be ideal. The rubber bushing is fine for me and unless I'm bored senseless sometime,I doubt I'll go back with the poly. Maybe just to see how it feels when installed properly.

I'll pollsters again after I've ran it a little harder. Break in period is over!!!!

terrasmak

iTrader: (8)

That's how they are, my break in always consists of driving it the way it's going to get driven.

My mounts are also Z1 poly, nothing to major

the rook

My poly bushing was installed all wrong.... long story. But I didnt know that was my vibration problem until I had it all apart and had bought the oem. So I went with the oem just to be sure. But yeah I'm guessing it wouldn't be much vibration with a poly. That being said, I don't race. So I didn't really need poly in the first place. Only ordered it because I'll always change the mount (and the rear main) when I change the clutch. Plus it was same price as the oem pretty much. I may go back with it next summer.

the rook

I should also mention that my in town gas mileage is significantly improved since installation. I would assume it's due to the 13.5 lb flywheel reducing the amount of work that the crank is doing. Went from just over 21mpg to more than 23. I'll be taking a road trip to Denver soon. Hoping for some really good highway mileage.

BluestreamDE

Glad you like the clutch and flywheel. I have a Nismo flywheel which a few lbs less than OEM, but id like to get a lighter flywheel one day like the JWT or Z1's. Thanks for your review.

the rook

No problem. I'll repost another update after I've put another thousand miles or so. See how it breaks in.

And I looked at the Nismo setup. Way beyond my price range though. $775 shipped for this setup. That's clutch and flywheel.

the rook

Oh and I read a lot of bad reviews on the z1 branded clutch and flywheel. Of course mostly just hearsay but I think they're an eBay type quality. I didn't want to risk it. Jim Wolfe has a sterling rep in the Z community.

the rook

So i got tired of staring at that ISR bushing in the garage and decided to reinstall it to spec.
The car doesn't vibrate like hell the way it did when the bushing was over tightened but man its got some cabin noise significance. I can hear every bit of noise in the driveline too. My flywheel chatter in cabin increased as well.
The car itself is much more responsive however and the shifts are very crisp!!!
I guess I'm gonna drive it for a while and see how I like it. I have a track day soon so I'll roll with it until after that for sure.

Does the vibration and noise diminish over time? I wouldn't think so because it's poly and probably not going to soften much. Lol.

Will poly diff bushings intensify the vibration during acceleration or will it only effect the car during launch and shifting?

Mukrat

iTrader: (1)

Hey the rook,
I have the same JWT carbon clutch flywheel combo. I have been running it for over 100,000 miles now (installed at 50,000 miles on car) and it still hooks up VERY well. The vibration and chatter does diminish a little from the initial, but not by much. Even now the chatter is loud enough for someone standing outside the car to notice it. Push the clutch in and the chatter goes away. You will also notice that you have to give it a little more gas/RPM before you can start to let the clutch out. The lighter weight seems to affect transmission engagement differently than when it was stock. This is a performance clutch/flywheel combo after all.

There are a couple "CONs" to the Flywheel/Clutch combo that you will begin to notice.
One which may or may not be related, is downshifts from 5th to 4th tend to grind every 4th or 5th time I downshift. This is of course under pressure so it may just be me.
Another is that every know and then (very irregular occurrences) you will go to start the car and get a loud grinding sound instead of the car starting. It sounds like the starter and flywheel and being grinded together. Just turn the key off and start it again, it will be fine. 100,000 miles and have not had any "real" problems other than these 2 items.

Now I am about to do a complete overhaul on my girl and will get the same clutch I got before. And when I say overhaul, I mean nearly everything is being changed, replaced or upgraded. It will be a SAGA!